Insurance in Force (Schedule Of Geographical Distribution Of Insurance In Force) (Detail) - USD ($) $ in Billions	Dec. 31, 2016	Dec. 31, 2015
Insurance in Force	$ 235.9	$ 326.6
% of Insurance in Force	100.00%	100.00%
California [Member]
Insurance in Force	$ 42.7	$ 55.5
% of Insurance in Force	18.10%	17.00%
New York [Member]
Insurance in Force	$ 16.6	$ 23.4
% of Insurance in Force	7.00%	7.10%
Illinois [Member]
Insurance in Force	$ 15.4	$ 20.5
% of Insurance in Force	6.50%	6.30%
Florida [Member]
Insurance in Force	$ 8.7	$ 15.2
% of Insurance in Force	3.70%	4.70%
Texas [Member]
Insurance in Force	$ 9.1	$ 14.5
% of Insurance in Force	3.90%	4.40%
New Jersey [Member]
Insurance in Force	$ 11.5	$ 13.7
% of Insurance in Force	4.90%	4.20%
Puerto Rico [Member]
Insurance in Force	$ 8.6	$ 9.0
% of Insurance in Force	3.60%	2.80%
Sub-Total Insurance In Force [Member]
Insurance in Force	$ 128.1	$ 171.0
% of Insurance in Force	54.30%	52.40%
Nationally Diversified [Member]
Insurance in Force	$ 20.4	$ 28.9
% of Insurance in Force	8.60%	8.90%
Other States [Member]
Insurance in Force	$ 57.0	$ 90.4
% of Insurance in Force	24.20%	27.60%
United States [Member]
Insurance in Force	$ 205.5	$ 290.3
% of Insurance in Force	87.10%	88.90%
Internationally Diversified [Member]
Insurance in Force	$ 0.5	$ 1.1
% of Insurance in Force	0.20%	0.30%
Country Specific [Member]
Insurance in Force	$ 29.9	$ 35.2
% of Insurance in Force	12.70%	10.80%
Non-United States [Member]
Insurance in Force	$ 30.4	$ 36.3
% of Insurance in Force	12.90%	11.10%
Virginia [Member]
Insurance in Force	$ 5.2	$ 6.2
% of Insurance in Force	2.20%	1.90%
Hawaii [Member]
Insurance in Force	$ 5.2	$ 6.1
% of Insurance in Force	2.20%	1.90%
Colorado [Member]
Insurance in Force	$ 5.1	$ 6.9
% of Insurance in Force	2.20%	2.10%